It could be as simple as "The Horde have some weak allies with bases near our main port, it shouldn't take many troops to wipe them out but it will reduce the unlikely chance of an assault from them...

The Draenei comprised a significant portion of Alliance content in TBC in addition to its neutral content, though they admittedly sat most of the next four expacts out. They then became the majority...

Let's also consider that, with Azeroth being a titan, that's likely the Earthmother worshiped by the tauren. That means their goddess is explicitly not an elemental, but if anything, she's an arcane...